Did other troops use the Mosin Nagant in Finland and are these marked in a certain manner?
Yes. A number of nations sent volunteers to Finland in the Finnish Civil War, the Winter War, and the Continuation War. These included but were are not limited to Swedes, Danes, Estonians (3,000-5,000 in WW2), and even Americans. No the rifles used by these forces are not marked in a certain manner.